1. Field of the Invention
The present invention relates to a measuring apparatus which measures the constituent concentration of a specimen after the specimen to be measured is applied to a test material of a test piece and the test piece is loaded, for example, a measuring apparatus which determines the concentration of constituents in blood.
2. Description of the Related Art
In a conventional blood constituent measuring apparatus, first blood to be measured is applied to test paper, and the test paper is loaded into the measuring apparatus. Then after lapse of a predetermined time period necessary for the test paper to react to the constituents of the blood, a measurement is started. Such test paper is generally housed in a small disposable container called a test piece in view of its maneuverability. A specimen of a substance to be measured, for instance, blood, is applied to test paper through an opening formed through this container, and the test piece together with this container are loaded into the apparatus. In this way, after loading this container into the apparatus, the test paper is irradiated with a light through an opening formed on the rear side of the opening, and the constituent concentration of a specimen is determined by measuring the reflected light intensity.
However, in the example of the prior art, even if the container is reversely loaded into the apparatus erroneously, the result of a measurement is output after the lapse of a predetermined time when the reaction of the test paper is completed, with the result that the fact that the container has been reversely loaded can be determined by an abnormal measurement result. For this reason, at the time this reverse insertion is found, since more than the predetermined time period has elapsed after the test paper had reacted to the blood, the test paper cannot be used again for a measurement, and therefore a measurement must be repeated from the beginning using another test paper. Further, the abnormal measurement result caused by a reverse insertion will be announced to the person under measurement as his result.
Of such conventional measuring apparatuses which measure constituents of a specimen, particularly in a blood sugar measuring apparatus, a test piece is loaded to a measuring apparatus after blood to be measured is applied to test paper of a test piece and excessive blood is wiped off, and after the lapse of a predetermined time when the test paper reacts to the blood constituents. After the loading is complete, by depressing a measurement start switch disposed on the measuring apparatus, a measurement of a blood sugar value is started.
In the above-mentioned example of the prior art, however, the predetermined time period until the test paper reacts must be measured by an operator, who is troubled by such operation. Thus, a mistake in measuring time may result in an inaccurate blood sugar value. Also, if the start switch is not depressed, a measurement is not started after the loading of a test piece. Therefore, even if time is measured accurately with much effort, a measurement cannot be made because the depressing of the start switch is forgotten. Or, a delay in depressing the start switch also result in an inaccurate blood sugar value.
Blood sugar values which have been measured in the above way are stored in a memory or the like of the apparatus together with measurement date and time information. The measurement date and time information stored along with such measurement result is very important information in taking a history of the blood sugar values of a person. In the conventional measuring apparatus, however, since a measurement can be made even if the date and time information is not set, and the information is stored in the memory, the stored blood sugar value itself is meaningless since the date when the information was measured is unknown.